searching for valid sample counts for MSAA in GL2 and GL3 instead of failing

changelog.txt

@@ -83,6 +83,8 @@ add: r_mapBrightness now works on q3map2's external lightmap atlas images
 add: the renderer can now batch surfaces with different (but sufficiently similar) shaders
   this new optimization works with the output of "Frozen Sand Particle Studio"
 
+chg: searching for valid sample counts for MSAA in GL2 and GL3 instead of failing right away
+
 add: /modellist /skinlist /imagelist /shaderlist can now filter results with pattern matching
 
 chg: SSE2 instruction set support is now required

code/renderer/tr_backend_gl2.cpp

@@ -51,6 +51,9 @@ static void RB_FogPass();
 static void GAL_Begin2D();
 static GLint GetTexEnv( texEnv_t texEnv );
 
+void GL_GetRenderTargetFormat( GLenum* internalFormat, GLenum* format, GLenum* type, int cnq3Format );
+void GL_CreateColorRenderBufferStorageMS( int* samples );
+
 
 struct GLSL_Program {
 	GLuint p;  // linked program
@@ -334,12 +337,12 @@ static unsigned int frameBufferReadIndex = 0; // read this for the latest color/
 static qbool frameBufferMultiSampling = qfalse;
 
 
-#define CASE( x )		case x: return #x
 #define GL( call )		call; GL2_CheckError( #call, __FUNCTION__, __FILE__, __LINE__ )
 
 
 static const char* GL2_GetErrorString( GLenum ec )
 {
+#define CASE( x )		case x: return #x
 	switch ( ec )
 	{
 		CASE( GL_NO_ERROR );
@@ -352,6 +355,7 @@ static const char* GL2_GetErrorString( GLenum ec )
 		CASE( GL_STACK_OVERFLOW );
 		default: return "?";
 	}
+#undef CASE
 }
 
 
@@ -377,53 +381,6 @@ static void GL2_CheckError( const char* call, const char* function, const char*
 }
 
 
-static const char* GL2_GetFBOStatusString( GLenum status )
-{
-	switch ( status )
-	{
-		CASE( GL_FRAMEBUFFER_COMPLETE );
-		CASE( GL_FRAMEBUFFER_UNDEFINED );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER );
-		CASE( GL_FRAMEBUFFER_UNSUPPORTED );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE );
-		CASE( GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS );
-		default: return "?";
-	}
-}
-
-
-#undef CASE
-
-
-void GL_GetRenderTargetFormat( GLenum* internalFormat, GLenum* format, GLenum* type, int cnq3Format )
-{
-	switch( cnq3Format )
-	{
-		case RTCF_R10G10B10A2:
-			*internalFormat = GL_RGB10_A2;
-			*format = GL_BGRA;
-			*type = GL_UNSIGNED_INT_2_10_10_10_REV;
-			break;
-
-		case RTCF_R16G16B16A16:
-			*internalFormat = GL_RGBA16;
-			*format = GL_BGRA;
-			*type = GL_UNSIGNED_SHORT;
-			break;
-
-		case RTCF_R8G8B8A8:
-		default:
-			*internalFormat = GL_RGBA8;
-			*format = GL_BGRA;
-			*type = GL_UNSIGNED_BYTE;
-			break;
-	}
-}
-
-
 static qbool GL2_FBO_CreateSS( FrameBuffer& fb, qbool depthStencil )
 {
 	while ( glGetError() != GL_NO_ERROR ) {} // clear the error queue
@@ -454,8 +411,7 @@ static qbool GL2_FBO_CreateSS( FrameBuffer& fb, qbool depthStencil )
 	const GLenum fboStatus = glCheckFramebufferStatus( GL_FRAMEBUFFER );
 	if ( fboStatus != GL_FRAMEBUFFER_COMPLETE )
 	{
-		ri.Printf( PRINT_ERROR, "Failed to create FBO (status 0x%X, error 0x%X)\n", (unsigned int)fboStatus, (unsigned int)glGetError() );
+		ri.Error( ERR_FATAL, "Failed to create FBO (status 0x%X, error 0x%X)\n", (unsigned int)fboStatus, (unsigned int)glGetError() );
-		ri.Printf( PRINT_ERROR, "FBO status string: %s\n", GL2_GetFBOStatusString(fboStatus) );
 		return qfalse;
 	}
 
@@ -474,16 +430,15 @@ static qbool GL2_FBO_CreateMS( FrameBuffer& fb )
 	GL(glGenFramebuffers( 1, &fb.fbo ));
 	GL(glBindFramebuffer( GL_FRAMEBUFFER, fb.fbo ));
 
-	GLenum internalFormat, format, type;
+	int sampleCount = 0;
-	GL_GetRenderTargetFormat( &internalFormat, &format, &type, r_rtColorFormat->integer );
 	GL(glGenRenderbuffers( 1, &fb.color ));
 	GL(glBindRenderbuffer( GL_RENDERBUFFER, fb.color ));
-	GL(glRenderbufferStorageMultisample( GL_RENDERBUFFER, r_msaa->integer, internalFormat, glConfig.vidWidth, glConfig.vidHeight ));
+	GL_CreateColorRenderBufferStorageMS( &sampleCount );
 	GL(glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, fb.color ));
 
 	GL(glGenRenderbuffers( 1, &fb.depthStencil ));
 	GL(glBindRenderbuffer( GL_RENDERBUFFER, fb.depthStencil ));
-	GL(glRenderbufferStorageMultisample( GL_RENDERBUFFER, r_msaa->integer, GL_DEPTH24_STENCIL8, glConfig.vidWidth, glConfig.vidHeight ));
+	GL(glRenderbufferStorageMultisample( GL_RENDERBUFFER, sampleCount, GL_DEPTH24_STENCIL8, glConfig.vidWidth, glConfig.vidHeight ));
 
 	GL(glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, fb.color ));
 	GL(glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, fb.depthStencil ));
@@ -491,8 +446,7 @@ static qbool GL2_FBO_CreateMS( FrameBuffer& fb )
 	const GLenum fboStatus = glCheckFramebufferStatus( GL_FRAMEBUFFER );
 	if ( fboStatus != GL_FRAMEBUFFER_COMPLETE )
 	{
-		ri.Printf( PRINT_ERROR, "Failed to create FBO (status 0x%X, error 0x%X)\n", (unsigned int)fboStatus, (unsigned int)glGetError() );
+		ri.Error( ERR_FATAL, "Failed to create FBO (status 0x%X, error 0x%X)\n", (unsigned int)fboStatus, (unsigned int)glGetError() );
-		ri.Printf( PRINT_ERROR, "FBO status string: %s\n", GL2_GetFBOStatusString(fboStatus) );
 		return qfalse;
 	}
 
@@ -500,6 +454,8 @@ static qbool GL2_FBO_CreateMS( FrameBuffer& fb )
 	fb.multiSampled = qtrue;
 	fb.hasDepthStencil = qtrue;
 
+	ri.Printf( PRINT_ALL, "MSAA: %d samples requested, %d selected\n", r_msaa->integer, sampleCount );
+
 	return qtrue;
 }
 
@@ -507,7 +463,7 @@ static qbool GL2_FBO_CreateMS( FrameBuffer& fb )
 static qbool GL2_FBO_Init()
 {
 	const int msaa = r_msaa->integer;
-	const qbool enable = msaa >= 2 && msaa <= 16;
+	const qbool enable = msaa >= 2;
 	frameBufferMultiSampling = enable;
 
 	if ( !enable )

code/renderer/tr_backend_gl3.cpp

@@ -650,6 +650,72 @@ static const char* downSample_cs =
 "	imageStore(dstTex, dstTC, r);\n"
 "}\n";
 
+
+void GL_GetRenderTargetFormat(GLenum* internalFormat, GLenum* format, GLenum* type, int cnq3Format)
+{
+	switch(cnq3Format)
+	{
+		case RTCF_R10G10B10A2:
+			*internalFormat = GL_RGB10_A2;
+			*format = GL_BGRA;
+			*type = GL_UNSIGNED_INT_2_10_10_10_REV;
+			break;
+
+		case RTCF_R16G16B16A16:
+			*internalFormat = GL_RGBA16;
+			*format = GL_BGRA;
+			*type = GL_UNSIGNED_SHORT;
+			break;
+
+		case RTCF_R8G8B8A8:
+		default:
+			*internalFormat = GL_RGBA8;
+			*format = GL_BGRA;
+			*type = GL_UNSIGNED_BYTE;
+			break;
+	}
+}
+
+void GL_CreateColorRenderBufferStorageMS(int* samples)
+{
+	GLenum internalFormat, format, type;
+	GL_GetRenderTargetFormat(&internalFormat, &format, &type, r_rtColorFormat->integer);
+
+	int sampleCount = r_msaa->integer;
+	while(glGetError() != GL_NO_ERROR) {} // clear the error queue
+
+	if(GLEW_VERSION_4_2 || GLEW_ARB_internalformat_query)
+	{
+		GLint maxSampleCount = 0;
+		glGetInternalformativ(GL_RENDERBUFFER, internalFormat, GL_SAMPLES, 1, &maxSampleCount);
+		if(glGetError() == GL_NO_ERROR)
+		{
+			sampleCount = min(sampleCount, (int)maxSampleCount);
+		}
+	}
+
+	GLenum errorCode = GL_NO_ERROR;
+	for(;;)
+	{
+		// @NOTE: when the sample count is invalid, the error code is GL_INVALID_OPERATION
+		glRenderbufferStorageMultisample(GL_RENDERBUFFER, sampleCount, internalFormat, glConfig.vidWidth, glConfig.vidHeight);
+		errorCode = glGetError();
+		if(errorCode == GL_NO_ERROR || sampleCount == 0)
+		{
+			break;
+		}
+
+		--sampleCount;
+	}
+
+	if(errorCode != GL_NO_ERROR)
+	{
+		ri.Error(ERR_FATAL, "Failed to create multi-sampled render buffer storage (error 0x%X)\n", (unsigned int)errorCode);
+	}
+
+	*samples = sampleCount;
+}
+
 #if defined(_WIN32)
 
 static void AllocatePinnedMemory(ArrayBuffer* buffer)
@@ -879,17 +945,16 @@ static void FBO_CreateMS(FrameBuffer* fb, const char* name)
 	glGenFramebuffers(1, &fb->fbo);
 	glBindFramebuffer(GL_FRAMEBUFFER, fb->fbo);
 
-	GLenum internalFormat, format, type;
+	int sampleCount = 0;
-	GL_GetRenderTargetFormat(&internalFormat, &format, &type, r_rtColorFormat->integer);
 	glGenRenderbuffers(1, &fb->color);
 	glBindRenderbuffer(GL_RENDERBUFFER, fb->color);
-	glRenderbufferStorageMultisample(GL_RENDERBUFFER, r_msaa->integer, internalFormat, glConfig.vidWidth, glConfig.vidHeight);
+	GL_CreateColorRenderBufferStorageMS(&sampleCount);
 	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, fb->color);
 	SetDebugName(GL_RENDERBUFFER, fb->color, va("%s color attachment 0", name));
 
 	glGenRenderbuffers(1, &fb->depthStencil);
 	glBindRenderbuffer(GL_RENDERBUFFER, fb->depthStencil);
-	glRenderbufferStorageMultisample(GL_RENDERBUFFER, r_msaa->integer, GL_DEPTH24_STENCIL8, glConfig.vidWidth, glConfig.vidHeight);
+	glRenderbufferStorageMultisample(GL_RENDERBUFFER, sampleCount, GL_DEPTH24_STENCIL8, glConfig.vidWidth, glConfig.vidHeight);
 	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, fb->depthStencil);
 	SetDebugName(GL_RENDERBUFFER, fb->depthStencil, va("%s depth/stencil attachment", name));
 
@@ -905,12 +970,14 @@ static void FBO_CreateMS(FrameBuffer* fb, const char* name)
 	fb->multiSampled = qtrue;
 	fb->hasDepthStencil = qtrue;
 	fb->hasColor = qtrue;
+
+	ri.Printf(PRINT_ALL, "MSAA: %d samples requested, %d selected\n", r_msaa->integer, sampleCount);
 }
 
 static void FBO_Init()
 {
 	const int msaa = r_msaa->integer;
-	gl.fbMSEnabled = msaa >= 2 && msaa <= 16;
+	gl.fbMSEnabled = msaa >= 2;
 
 	if(gl.fbMSEnabled)
 	{

code/renderer/tr_init.cpp

@@ -367,7 +367,7 @@ static const cvarTableItem_t r_cvars[] =
 	{ &r_d3d11_syncOffsets, "r_d3d11_syncOffsets", "2", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "0", XSTRING(D3D11SO_MAX), help_r_d3d11_syncOffsets },
 	{ &r_d3d11_maxQueuedFrames, "r_d3d11_maxQueuedFrames", "3", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "1", "16", help_r_d3d11_maxQueuedFrames },
 	{ &r_ext_max_anisotropy, "r_ext_max_anisotropy", "16", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "0", "16", help_r_ext_max_anisotropy },
-	{ &r_msaa, "r_msaa", "0", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "0", "16", "anti-aliasing sample count, " S_COLOR_VAL "0" S_COLOR_HELP "=off" },
+	{ &r_msaa, "r_msaa", "0", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "0", "32", "anti-aliasing sample count, " S_COLOR_VAL "0" S_COLOR_HELP "=off" },
 	{ &r_picmip, "r_picmip", "0", CVAR_ARCHIVE | CVAR_LATCH, CVART_INTEGER, "0", "16", help_r_picmip },
 	{ &r_roundImagesDown, "r_roundImagesDown", "0", CVAR_ARCHIVE | CVAR_LATCH, CVART_BOOL, NULL, NULL, help_r_roundImagesDown },
 	{ &r_colorMipLevels, "r_colorMipLevels", "0", CVAR_LATCH, CVART_BOOL, NULL, NULL, "colorizes textures based on their mip level" },